package student;

import java.util.ArrayList;
import java.util.Scanner;

public class StudentSystem {
    public static void main(String[] args) {
        ArrayList<Student> list = new ArrayList<>();
        loop:
        while (true) {
            System.out.println("===========欢迎来到学生管理系统=============");
            System.out.println("1. 添加学生");
            System.out.println("2. 删除学生");
            System.out.println("3. 修改学生");
            System.out.println("4. 查询学生");
            System.out.println("5. 退出");
            System.out.println("请输入你的选择:");
            Scanner sc = new Scanner(System.in);
            String choose = sc.next();
            switch (choose) {
                case "1" -> addStudent(list);
                case "2" -> delStudent(list);
                case "3" -> updateStudent(list);
                case "4" -> quaryStudent(list);
                case "5" -> {
                    System.out.println("退出");
                    // System.exit(0);
                    break loop;
                }
                default -> System.out.println("没有这个选项");
            }
        }
    }

    //添加学生
    public static void addStudent(ArrayList<Student> list) {
        //利用空参构造创建学生对象
        Student s = new Student();
        Scanner sc = new Scanner(System.in);

    while(true) {
        System.out.println("请输入学生的id");
        String id = sc.next();
        boolean flag = contains(list, id);
        if (flag) {
            System.out.println("id已经存在,请重新录入");
        }else{
            s.setId(id);
            break;
        }
    }


        System.out.println("请输入学生的姓名");
        String name = sc.next();
        s.setName(name);
        System.out.println("请输入学生的年龄");
        int age = sc.nextInt();
        s.setAge(age);
        System.out.println("请输入学生的家庭住址");
        String address = sc.next();
        s.setAddress(address);
       //把学生对象添加到集合中
        list.add(s);
        //提示用户
        System.out.println("学生信息添加成功");
    }

    //删除学生
    public static void delStudent(ArrayList<Student> list) {
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入要删除的id");
        String id = sc.next();
        int index = getIndex(list,id);
        if(index>=0){
            list.remove(index);
            System.out.println("id为:"+id+"的学生删除成功");
        }else{
            System.out.println("id不存在,删除失败");
        }
    }

    //修改学生
    public static void updateStudent(ArrayList<Student> list) {
        System.out.println("请输入你要修改的id");
        Scanner sc = new Scanner(System.in);
        String id = sc.next();
        int index = getIndex(list,id);
        if(index==-1){
            System.out.println("要修改的id"+id+"不存在,请重新输入");
            return;
        }
            Student stu = list.get(index);

            System.out.println("请输入要修改的学生姓名");
            String newName = sc.next();
            stu.setName(newName);

            System.out.println("请输入要修改的学生年龄");
            int newAge= sc.nextInt();
            stu.setName(String.valueOf(newAge));

            System.out.println("请输入要修改的家庭地址");
            String newAddress= sc.next();
            stu.setName(newAddress);
        }



    //查询学生
    public static void quaryStudent(ArrayList<Student> list) {
        if (list.size() == 0) {
            System.out.println("当前无学生信息,请添加后查看");
            return;
        }
        System.out.println("id\t姓名\t年龄\t家庭住址");
        for (int i = 0; i < list.size(); i++) {
            Student stu = list.get(i);
            System.out.println(stu.getId() + "\t" + stu.getName() + "\t" + stu.getAge() + "\t" + stu.getAddress());
        }
    }
    //判断id是否存在
    public static boolean contains(ArrayList<Student> list,String id){
      /*  for (int i = 0; i < list.size(); i++) {
            if(list.get(i).getId().equals(id)){
                return true;
            }
        }
        return false;
       */
        return getIndex(list,id)>=0;
    }
    //通过id返回索引
    public static int getIndex(ArrayList<Student> list,String id){
        for (int i = 0; i < list.size(); i++) {
            if(list.get(i).getId().equals(id)){
                return i;
            }
        }
        return -1;
    }
}
